Transfer storage counters



Sept. 29, 1959 R. w. WOLFE 2,906,915

TRANSFER STORAGE COUNTERS Filed Aug. 21, 1957 o +s5v, VCATHODE MULTMBRATOR 44 +|5 v FIG. I

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ROGER W. WOLFE 2,906,915 Patented Sept. 29, 1959 United States Patent Qflice TRANSFER STORAGE COUNTERS This invention relates to transfer. storage counters. A transfer storage counter generally comprises apparatus for counting or sampling electrical signals representative of events occurring during a selected time interval and for storing a count at a predetermined'time. Transfer storage counters of the prior art are generally unsatisfactory because they ordinarily do not sample and store at the same time so that when the storage function is being performed, the sampling function is suspended and, as a result, some of the sampling count is lost. In addition, prior art systems generally employ binary counters so that decoders are required to translate from a binary to a decimal system. Moreover, the prior art systems are undesirably complex.

Accordingly, one object of the invention is to provide an improved transfer storage counter.

Another object of the invention is to provide an improved and generally simplified transfer storage counter of the decimal counting type capable of sampling and holding a count in storage at the same time.

A transfer storage counter embodying the present invention employs electron beam Switching tubes of the type shown in US. Patent No. 2,721,955 to Fan et al. These tubes include a central longitudinally elongated electron emitting cathode and a plurality of groups of electrodes arrayed about the cathode. Each group of electrodes includes an electron beam forming electrode known as a spade electrode, an electron beam target electrode, and an electron beam switching electrode. A cylindrical permanent magnet surrounds each tube and provides an axially aligned magnetic field within the tube. This magnetic field and the electric field provided by electrode potentials are utilized to switch an electron beam from one group of electrodes to the next.

In brief, a transfer storage counter according to the invention includes two such electron beam switching tubes, one of which is operated as a counting tube, and the other of which is operated as a storage tube. Each group of electrodes in the counting tube is directly connected to a corresponding group of electrodes in the storage tube, the connection being such that current flow to one of the groups of electrodes inthe counting tube provides a bias condition in the corresponding group of electrodes in the storage tube, which makes the latter group of electrodes susceptible to storing a count; The count is actually stored by cutting off the storage tube, by removing its operating voltage and then allowing the tube to resume operation by slowly restoring its operating voltage. As the voltage increases, it passes through a critical value at which an electron beam forms on the group of electrodes biased by the current in the counting tube.

The invention is described in greater detail by reference to the drawing wherein:

Fig. l is a schematic representation of a system bebodying the invention; and

Fig. 2 is a schematic representation of a modification of the system of Fig. 1.

Referring to Fig. 1, a transfer storage counter according to the invention includes two electron beam switching tubes 10 and 12 of the type shown in U.S, Patent No. 2,721,955 to Fan et al. In actual construction,fitheseftubes are cylindrical in form; however, for convenience, they are shown schematically in linear form. The tube 10 is the counting tube of the system and the tube 12 is the storage tube of the system. The tubes ordinarily include a cathode and ten groups of electrodes arrayed about the cathode. However, again for simplicity, only four of these groups of electrodes are shown, numbered 0,.1, 2, and 9, in each tube. Tube 10 includes a cathode 14 and each of the groups of elec trodes includes a generally U-shaped longitudinally elongated beam forming and holding electrode 16, called a spade electrode, a generally L-shaped longitudinally elongated target or output electrode 18, and rod-like switching electrode 20. An open-ended cylindrical permanent magnet (not shown) surrounds the tube 10 and is coaxial therewith and provides an axial magnetic field within the tube which is oriented to urge electrons from the cathode either clockwise or counter-clockwise, depending on the orientation of the magnetic field H. The magnetic field strength is selected to provide a desired magnetron cut-off voltage and operating tube current. The second tube is a duplicate of the. first tube and includes a cathode 14', spade electrodes 16', target electrodes 18, switching electrodes 20', and a cylindrical magnet (not shown). An output terminal 21 is connected to each target electrode 18' for connection to a suitable utilization device, for example, a visual indicator, relays, printing mechanism or the like.

Referring to Fig. '1 and to tube 10, the cathode 14 is connected through a bias resistor 22 to a source of reference potential such as ground. Each spade electrode is connected through a spade load resistor 24 to a common spade buss 26 which carries a terminal 28. The terminal 28 is coupled to a power source (not shown) which provides a positive DC. voltage of the order'of 85 volts above cathode voltage and to a source (not shown) of positive square wave pulses 30. Each target electrode 18 is coupled through a load resistor 32 to a common target buss 34 which carries a terminal 36 at which a positive D.C. supply voltage of the order of 150 volts is provided.

The switching electrodes 20 of the tube 10 may be connected in any one of a number of suitable ways to provide the desired switching operation of an electron beam from position to position. According to one suitable method as shown, the switching electrodes are con-, nected in two sets with alternate electrodes being connected together in each set. The two sets of switching electrodes are coupled to a suitable source of switching pulses such as a bistable multivibrator 38. Each out-' put pulse from the multivibrator serves to switch an electron beam in the tube from one position to the next.

In addition, means for zero-setting the tube, that is, interrupting a counting operation and starting a count again at a predetermined position may also be provided. Suitable circuits for this purpose are shown in U.S Patent No. 2,794,147 to Bethke. For purposes of simplification, no specific zero-setting means is shown in the drawing or described herein.

In tube 12, the target electrodes 18' are connected through load resistors 40 to a common target buss 42 having a terminal 44 at which a positive D.C. supply voltage of the order of volts is provided. Each spade 16 is connected through a coupling resistor 46 directly to the spade electrode 16 of the corresponding group of electrodes in tube 10. Thus, the spade 16' at position 1 in tube 12 is connected directly to the target 20 at position 1 in tube 10. The switching electrodes 20- are connected together and to a terminal 49 at which a positive supply voltage of the order of 150 volts is provided. This connection of the switching electrodes to a. comparatively high positive potential prevents spurious switching on formation of an electron beam in the storagetube.

Forreasons to be discussed below, it may be desirable to connect the targets at positions 0, l, 2 9 in that order in the counting tube. 10 to positions 9-, 8, 7 in that order in the storage tube 12. a

A circuitis provided for cutting off and then turning on the tube 12 by the application of electricalpulses thereto. This circuit includesan electron discharge device, for'example, a triode tube 48 having a cathode 50 connected through a bias resistor 52 to a terminal 54 at which" a negative bias voltage is provided. Control grid 56 of the tube 48. is connected. through a suitable bias resistor 58. to the terminal 54 and is coupled by a suitable coupling capacitor 60 to a terminal 62 at which negative-square wave voltage,- pulses 63 are provided. Anode 64 of tube 48 is connected through a resistor 66 directly to the cathode 14 of tube 12. A capacitor 68- is connected in parallel with the load resistor 66 and the anode-64 is coupled both through a diode 70 to ground and through a resistor- 72 to a terminal 74 at which a positive supply voltage of the order of 150 volts is provided.

Inoperation of the transfer storage counter shown in Fig. 1, an electron beam is formed in tube and is switched from position toposition by means of pulses from the multivibrator 38. This represents the desired counting operation of the tube 10. As the electron beam fiows toeach target 1-8 in turn, the voltage on the corresponding spade 16', to which the target is connected, is reduced. This reduction in spade voltage is not sufiicient by itself to cause a beam to form in the storage tube. However, it is suflicient to facilitate the formation of' a beamwhen accompanied by another operation to be described. For tubes of the type under consideration and with suitable target load resistors 32, this reduction in voltageis arranged to be of the order of 10 or -volts.

When at any instant, it is desired to transfer the count from the counting tube 10 to the storage tube 12, a negative square wave voltage pulse 63, which acts as a gate, is applied to the control grid 56 of the tube 48 and this cuts off the tube 48. When the tube 48 is cut off, the voltage of the cathode 14 of tube 12 is raised to about spade voltage (150 volts) and the tube 12 is cut off and cleared of an electron beam which might have been present in one of its positions. At the termination of the. negative pulse 63, the control. grid 56 returns to itsanormal bias voltage and the tube 48 begins to conduct. At the same time, thecathode 14" begins to emit electrons, the voltage ofthe cathode begins to decrease from spade voltage and the voltage across the storage tube.12"(spade-t'o-cathode) begins to increase. The rate at which the voltage across the storage tube 12 increases is determined by the time constant of the combination of the resistor 58 andcapacitor 60 and this time constant is designed to' be comparatively high so that the voltage increases comparatively slowly. As the voltage across the tube 12 increases, a voltage level. is reached at which an electron beam from the cathode 14' forms in the position having. the spade electrode 16 which is connected to the target electrode 20 in the counting tube 10, in. which the counting electron beam is located. The storage electron beam forms on this spade because its voltage has been lowered due to the flow of current to the target inthe countingtubeto which it is connected. It is desirable that the voltage. across the storage tubev increase slowlyso. that the voltage. level at which. the storagebeam forms isInot passed through too quickly.

Ifthe rise is too rapid, the storage beam cannot form and reach a stable holding condition.

The formation of the beam in the selected position in the storage tube is facilitated by an auxiliary operation as follows. A positive square wave voltage gating pulse 38 is timed to coincide with the count transfer operation and is applied to the spade buss 26. The resultant increase in spade voltage increases the current flow to the target electrode 18 which is receiving the beam. This momentary increase in current lowers the corresponding spade in the storage tube 12 still more and aids the formation of a beam thereon. After the desired count has been stored and. the counting tube continues its counting operation, a succeeding count may be transferred to, and stored in, the storage tube at any desired time in the manner described above.

The reason for sometimes modifying the method of interconnecting the counting and storage tubes may now be, considered; This modification comprises connecting the: targetsat positions 0, l, 2 9, in that order, in thecountingtube to positions 9, 8, 7 0, respectively, in that order, in the storage tube. The magnetic field in each tube is oriented so that the electron beamtends to move from position 0 to I to 2, etc. The beam ordinarily cannot go backwards, that is, from position 9 to 8 to 7, etc. Thus, if the same corresponding positions in each tube are interconnected as shown in Fig. 1, when a count has been transferred, say, from position 1 in the counting tube to 1 in the storage tube,v and the beam, in the counter tube switches to position 2, the resultant lowering of the voltage of thespade 16' in position 2 of the storage 1 tube may be suflicient to switch the beam to position 2 in the storage tube. This undesired switching may occur if the storage electron beam has not had sufficient time toreach a stable holding condition in position 1. With the modified interconnection of the tubes, after the count has been stored in position 1 of the storage tube and the counting beam has moved to position 2 in the counting tube, which is connected to position 8 in the storage tube, the storage beam cannot move backwards, due to any instability, to position 8." Thus, the storage beam remains in position 1 and assumes a stable holding condition until the storage tube is cleared for the next transfer and storage operation.

A modified transfer storage counter shown in Fig. 2 includes all of the elements of the system shown in Fig. 1. However, in this modification, a diode 76 is connected from each target electrode 18 of the counting tube 10 to a buss 78 which is coupled through a terminal 80 to a source (not shown) of a comparatively high positive potential of the order of 150 volts. The

diodes 76 are thus biased in the forward direction and spect to Fig. 1.

present a low impedance to the targets 18. A source (not shown) of negative square wave voltage pulses 82 of the order of 50 volts is also connected to the buss 78.

In operation of the circuit of Fig. 2, the counter tube 10 functions in the manner described above with re- Since the diodes 76 are biased in the forward. direction, they'present a low impedance current path to each target 18 and the target current tends to follow this path. Accordingly, the resultant voltage drop of each target, as it receives the counting electron beam, is small and does not lower the voltage of the connected spade 16. appreciably. When a negative pulse 82 is applied to the buss 78 and to the diodes, it, in effect, biases the diodes in the reverse direction, and the diodes thus present a high impedance to the target. Thus, in the counting tube, current flows to a target 18 and through the target load resistor 32 and the desired lowering of the voltage of the connected spade 16' is achieved. This operation is accompanied by the cutting off, and subsequent turning on, of the cathode control triode 54 in themanner described above with respect to Fig. 1 so that a storage beam forms in the desired position.

The beam switching tubes and 12 described above trodes of these tubes may be enclosed in a single envelope, if desired.

In addition, the transfer. storage counters described above may be cascaded to provide a system which counts and stores a plurality of signals at the same time.

-What is claimed is:

l. A transfer storage counter comprising a first electron emitting cathode and a first group of electrodes arrayed about said cathode; a second electron emitting cathode and a second group of electrodes arrayed about said second cathode; each of said groups of electrodes including an electron beam forming and holding electrode, an

electron beam target electrode, and an electron beam switching electrode; each target electrode of said first group of electrodes being connected to a beamv forming and holding electrode of said second group of electrodes; current flow control means coupled to said second cathode of said second group of electrodes; and means coupled to said current fiow control means for controlling the rate at which current flows therethrough.

' 2. A transfer storage counter comprising first and second electron beam switching tubes; each tube including an electron emitting cathode and a plurality of groups of electrodes arrayed about said cathode; each of said groups of electrodes including an electron beam forming and holding electrode, an electron beam target electrode, and an electron beam switching electrode; each target electrode of one of said tubes being connected through an impedance to a beam forming and holding electrode of the other of said tubes; current flow control means coupled to the cathode of said other of said tubes for cutting off and turning on said last-mentioned cathode; and means coupled to said current flow control means for controlling the rate at which it turns on said last-mentioned cathode.

3. A transfer storage counter comprising first and second electron beam switching tubes; each tube including an electron emitting cathode and a plurality of groups of electrodes arrayed about said cathode; each of said groups of electrodes including an electron beam forming and holding electrode, an electron beam target electrode, and an electron beam switching electrode; each target electrode of one of said tubes being connected through an impedance to a beam forming and holding electrode of the other of said tubes; means for interrupting the operation of the other of said tubes and then slowly returning said other of said tubes to its operative state; and means for applying a voltage pulse to the beam forming and holding electrodes of said one tube.

4. A transfer storage counter comprising first and second electron beam switching tubes; each tube including an electron emitting cathode and a plurality of groups of electrodes arrayed about said cathode; each of said groups of electrodes including an electron beam forming and holding electrode, an electron beam target electrode, and an electron beam switching electrode; each target electrode of said first .tube being connected to a beam forming and holding electrode of said second tube; an electron dlscharge device coupled to the cathode of said second tube; circuit means for first cutting off and then turning on both said electron discharge device and the cathode of said second electron beam switching tube; and means coupled to said discharge device for controlling the rate at which it is turned on.

5. The counter defined in claim 4 wherein said lastnarned means includes a resistor-capacitor combination having a comparatively long time constant so that the cathode of said second tube is adapted to be returned slowly to operating voltage after it has been cut off.

6. The counter defined in claim 4 wherein said electron discharge device includes an output electrode and a signal input electrode; said output electrode being connected to the cathode of said second tube through an impedance; said output electrode being connected both through a di' ode to ground and through' a resistor-capacitor combination to a source of positive voltage; said resistor-capacitor combination having a long time constant; and means for applying pulses to said control electrode by which the operation of said electron discharge device may be controlled.

7. The counter defined in claim 4 and including a pulse source coupled to said first tube 'for facilitating a count transfer operation.

8. The counter defined in claim 4 and including a pulse source coupled to said beam forming and holding electrodes and operating in conjunction with said electron dis charge device to facilitate a count transfer operation.

9. A transfer storage counter comprising first and second magnetron beam switching tubes; each tube including an electron emitting cathode and a plurality of groups of electrodes arrayed about'said cathode; eachof said groups. of electrodes including an electron beam target electrode, a spade electrode for forming and holding an electron beam on its target electrode, and an electron beam switching electrode; each tube having a character istic direction of rotation of its electron beam; each target electrode of one tube being connected to a spade electrode of the other tube; current flow control means coupled to the cathode of one of said tubes; means coupled to said current flow control'm'eans for controlling therate at which current flows therethrough; and means coupled to said one tube for facilitating the transfer of a signal from said one tube to said other tube.

10. The counter defined in claim 9 wherein said lastnamed means includes a pulse source coupled to the spade electrodes of said one tube.

11. A transfer storage counter comprising first and second magnetron beam switching tubes; each tube including an electron emitting cathode and a plurality of groups of electrodes arrayed about said cathode; each of said groups of electrodes including an electron beam target electrode, a spade electrode for forming and holding an electron beam on its target electrode, and an electron beam switching electrode; each tube having a characteristic direction of rotation of its electron beam, with the groups of electrodes considered to be numbered 0, l, "2 n in order in the direction of rotation; each target electrode of one tube being connected to a spade electrode of the other tube, the connections being made in reverse order with the O target connected to the n spade electrode, the 1 target connected to the n1 spade, and so forth; current flow control means coupled to the cathode of one of said tubes; means coupled to said current flow control means for controlling the rate at which current flows therethrough; and means coupled to said one tube for facilitating the transfer of a signal from said one tube to said other tube.

12. The counter defined in claim 11 wherein said lastnamed means includes a pulse source coupled to the spade electrodes of said one tube.

13. A transfer storage counter comprising first and second multiple position electron beam switching tubes; each tube including an electron emitting cathode and a plurality of groups of electrodes arrayed about said cathode; each of said groups of electrodes including a target electrode adapted to receive an electron beam and produce an output signal and a spade electrode adapted to form and hold an electron beam on its associated target electrode; each target electrode of said first tube being connected to a spade electrode of said second tube; driving means coupled to said first tube for switching an electron beam from position to position; means coupled to said second tube for turning it off and then turning it on and thereby forming an electron beam at a position corresponding to the position of an electron beam in said first tube; and means clamping said interconnected target and spade electrodes to a reference potential whereby said second tube is substantially un- 7 affected by. the switching of an electron beam from position to position in said first tube.

14. A transfer storage counter comprising. first and second multiple position electron beam switching tubes; each tube including an electron emitting cathode-.and a plurality of groups of electrodes arrayed. about said cathode; each of. said groups, of electrodes including. a target electrode adapted to receive an electron. beam and produce an output. signal and aspade, electrode adapted to form and hold an electron beam on its associated target electrode; each target electrode of said first tube being connected to a spade electrode of said second tube; driving means coupled to said first tube for-switching an electron beam from position toposition; means coupled to said secondtube for turning it off and then turning it on and thereby forming an electron-beam at a position corresponding to the position of an electron beam in said first tube; and diode means clamping said interconnected target and spade electrodes to a reference potential whereby the spade electrodes of said second tube are substantially unaffected by the switching of a beam from position to position in said first tube.

15. A transfer storage counter comprising first and second multiple position electron beam switching tubes; each tube including an electron emitting cathode and a plurality of groups of electrodes arrayed about said cathode; each of said groups of electrodes including a target electrode adapted to receive an electron beam and produce an output signal, a spade electrode adapted to form and hold an electron beamonits associated target electrode; each target electrode of said first tube being connected to aspade electrode of said second tube; driving means coupled to said first tube for switching an electron beam from position to position; means coupled to said second tube for turning it off and then turning it on and thereby forming an electron beam. at a position corresponding to the position of an electron beam in said first tube; and means for applying a voltage pulse to the spade electrodes of said first tube to facilitate the transfer of a count from said first tube to said second tube.

16. The counter defined in claim. 15 andincluding means clamping said interconnected target and spade electrodes to a reference potential whereby said second tube is substantially unaffected by the switching of an electron beam from positionto position in said first tube.

17. Thecounter defined in claim 15 and including diode means clamping said interconnected target and spade electrodes to a reference potential whereby the spade electrodes of said second tube are substantially unaffected by the switching of a beam from. position to position in said first tube.

18. A transfer storage counter comprising first and second multi-position magnetron beam switching. tubes, means, coupling said tubes together,,said first: tube comprising a counter tube and said second tube comprising a storage tube. to which a countis transferred; from. said first. counter tube, driving means coupled to said first tube for-causingit to count,v controlmeans coupled to said second tube for turning it OK and then turning it on so that an electron beam forms in said second tube at a position determined by the position of an electron beam in said first tube, and other means coupled to said second tube for controlling the rate at which it is turned 19. A transfer storage counter comprising first and second multi-position magnetron beam switching tubes, connection means coupling said tubes together, said first tubecornprising a counter tube and said second tube comprising a storagetube to which a count is transferred from said first counter. tube, driving means coupled to said first tube for. causing it. to count, control means coupled to said. second tube for turning it off and then turning it on so that an electron beam forms in said secondtube at a position determined by the position of an electron beam in said first tube, time delay control means coupled to said second. tube for controlling the rateat which it is turnedon, and clamp means coupling said connection means to a reference potential whereby said second tube is unaffected bythe counting operation performed by said first tube until it is desired to transfer a count from said first tube to said second tube.

20. A transfer storage counter comprising, first and second multipleposition electron beam switching tubes; each tube including an electron emitting cathode and a plurality of groups of electrodes arrayed about said cathode; each of said groups of electrodes including a target electrode adapted to receive an electron beam and produce an output signal and a spade electrode adapted to formand hold an electron beam on its associated target electrode; each target electrode of said first tube being connected to a spade electrode of said second tube; driving means coupled to said first tube for switching an electron'beam from position to position; means coupled to said second tube for turning it off and then turning it onand thereby forming an electron beam at a position corresponding to the position'of an electron beam'in. said first tube; and means coupledto said second tube for controlling therate at which it is turned on.

References Cited in the file of this patent UNITED STATES PATENTS 2,733,409 Kuchinsky Jan. 31, 1956 2,758,790 Brian Aug. 14, 1956 2,794,147 Bethke May 28, 1957 

